A legislative act , directed against a designated person, pronouncing him guilty of an alleged crime, (usually treason,) without trial or conviction according to the recognized rules of procedure , and passing sentence of death and attainder upon him. “Bills of attainder,” as they are technically called, are such special acts of the legislature as inflict capital punishments upon persons supposed to be guilty of high offenses, such as treason and felony, without any conviction in the ordinary course of judicial proceedings . If an act inflicts a milder degree of punishment than death, it is called a ” bill of pains and penalties ,” but both are included in the prohibition in the Federal constitution . Story, Const.
Black’s Law Online Dictionary
